Thread-controlling device for sewing machines



Dec. 31, 1935. M CARD THREAD CONTROLLING DEVICE FOR SEWING MACHINES Filed April 13, 1935 4g 45 3mm fiezleric M Uard QPHVW 17.55 I

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Patented Dec. 31, 1935 UNITED STATES PATENT OFFICE THREAD-CON TROLLIN G DEVICE FOR SEWING MACHINES Application April 13, 1935, Serial No. 16,127

'7 Claims.

This invention relates to improvements in thread-controlling devices for sewing machines and more particularly in devices employed in conjunction with needle-thread take-up mechanisms for controlling slack thread.

The primary object'of the present invention is to provide improved means for individually controlling the needle-threads of a sewing machine having a plurality of needles. A more specific object of the present invention is to provide convenient means for regulating the efiective action of duplex slack-thread controllers.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawing of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawing, Fig. 1 represents a perspective view of a portion of a sewing machine containing the improved slack-thread controller. Figs. 2 and 3, respectively, are enlarged front and rear side views of the controller. Fig. 4 represents a cross-section of the controller substantially on the line 44 of Fig. 2.

The sewing machine illustrated in the drawing has a work-support including a throat-plate I provided with needle-apertures 2. overhanging the work-support is a bracket-arm head 3 in which is journaled a needle-bar 4 carrying at its lower end a needle-holder 5 in which needles 6 and 1 are secured. Also journaled in said bracketarm is a presser-bar 8 to the lower end of which a compensating presser-foot 9 is suitably secured. The sewing machine has a vibratory take-up lever ||l provided with spaced thread-eyes H and I2, which take-up lever functions toset the stitches in the usual manner.

During its downward movement, following upon its stitch-setting action, the take-up lever l0 provides slack thread which, in a lock-stitch sewing machine, is utilized in the casting of needlethread loops by a loop-taker about a mass of under thread. As is well understood, it is a primary function of slack-thread controllers of the present type to hold the needle-thread surficiently taut, during the initial downward movement of the take-up lever, to retard downward movement of the thread before the needle-eye enters the work. When more than one needle |s employed, i. e., more than one needle-thread, there are occasions requiring individual control of each of the needle-threads and it is to that end that the present improvement has been devised,

although it is to be understood that the present invention is not limited to any particular sewing machine or type of stitch-forming mechanism. 5 Suitably secured upon the front side of the machine bracket-arm is a tension-plate l3 upon which are mounted the usual thread-tension devices I4 and 5. Secured by screws I6 upon the tension-plate |3is a slack-thread controller sup- 10 porting plate I! which is bent outwardlyadja thimbles 22 and 23, each having an outer end wall apertured to receive a reduced outer end 24 or 25 of said stud-pins to which the respective thimbles are secured by set-screws 26 and 21, 5 whereby the thimbles may be individually turned about their supporting stud-pins into different set positions of said thimbles. The inner rims 28 and 29 of the thimbles are spaced from the adjacent faces of the supporting plate I! to pro- 30 vide clearance gaps for relatively yielding slack thread controller arms 30 and 3|, disposed at opposite sides of the plate I! and terminating at their free ends in open thread-receiving loops 32 and 33. The controller arms 30 and 3| extend 5 outwardlyfrom coil-springs 34 and 35 which surround the stud-pins l8, l9 and are housed in the thimbles 22, 23. The coil-springs 34, 35 are anchored to their respective housing thimbles 22,

23 by having the inner ends 36 and 37 of said 40 springs entering apertures 38 and 39 in said thimbles. The thimbles are preferably provided with a plurality of apertures 38 and 39 which may be selectively used to anchor the coil-springs 34, 35.

Embracing the thimbles 22, 23, to segmentally 45 close the gaps between the thimble rims 28, 29 and the supporting plate H, are segmental disks 4!] and 4|, providing opposed abutments 42, 43 and e4, 45, respectively. The disk All is provided 50 with an arcuate slot 46 entered by a disk-securing screw 41 threaded into the supporting plate I! from the front face thereof, thereby providing for adjustment of said disk 40. The disk 4| is adjustably secured by a screw 48 also having its head at the front side of the supporting plate l1, said screw 48 passing through an arcuate slot 49 in the plate I! and being threaded into the disk 4|.

It will therefore be understood that the described arrangement provides means, (Fig. 2), accessible from the front of the supporting plate, for individually adjusting the disks 40 and 4| about the thimbles 22, 23, thereby adjusting the positions of the controller arm a-butments provided by said disks and varying the efiective action of the controller-arms 39, 3|. By adjusting the thimbles 22, 23 angularly about the stud-pins l8, l9, the tensions exerted by the springs upon the controller-arms 39, 3| may be individually varied.

Each of the controller-arms 30, 3| acts in the usual manner to control a needle-thread. As illustrated by dot-dash lines in the drawing, two needle-threads A and B are passed through apertures in a conventional thread-guide 5B, and between the disks of the tension devices M, I5. The threads are then passed about thread-directing posts 5| and 52, carried by the tension-plate I3, and each through a loop of the controllerarms 39, 3| and then through the thread-eyes and I2 in the take-up lever ID, from which the threads pass through suitable thread-guides to the needles 6 and As the controller-arms 3E1, 3| each acts upon one thread only, the threads are individually controlled, the described arrangement providing for conveniently regulating the eifective action of said controller-arms.

Having thus set forth the nature of the invention, what I claim herein is:--

1. A slack-thread controlling device for sewing machines comprising, a supporting plate, slack-thread controllers disposed at opposite sides of said plate, and means accessible from one side of said supporting plate for individually varying the eifective action of said controllers.

2. A slack-thread controlling device for sewing machines comprising, a supporting plate, slack-thread controlling springs disposed at opposite sides of said plate, an adjustable abutment for each of said springs, and means accessible from one side of said supporting plate for individually effecting adjustment of said abutments.

3. A slack-thread controlling device for sewing machines comprising, a supporting plate, stud-pins carried by said supporting plate to extend from opposite faces thereof, coil-springs surrounding said stud-pins and providing yielding thread-controller arms, individually adjustable anchorages for said springs, and individually adjustable abutments for said thread-controller arms disposed at opposite sides of said supporting plate.

4. A slack-thread controlling device for sewing machines comprising, a supporting plate, alined stud-pins carried by said supporting plate to extend from opposite faces thereof, thimbles adjustably secured upon said stud-pins, coil-springs housed by and anchored to said thimbles, said coil-springs providing relatively yielding threadcontroller arms, and individually adjustable abutments for said arms.

5. A slack-thread controlling device for sewing machines comprising, a supporting plate, studpins carried by said supporting plate to extend from opposite faces thereof, thimbles adjustably secured upon said stud-pins in spaced relation to the opposite faces of said supporting plate, coilsprings housed by and anchored to said thimbles,

said coil-springs terminating in yielding threadcontrolling arms extending between said thimbles and said supporting plate, and abutments for said arms adjustably secured upon said supporting plate.

6. A slack-thread controlling device for sewing machines comprising, a supporting plate, studpins carried by said supporting plate to extend from opposite faces thereof, thimbles adjustably secured upon said stud-pins in spaced relation to the opposite faces of said supporting plate, coilsprings housed by and anchored to said thimbles, said coil-springs terminating in yielding threadcontrolling arms extending between said thimbles and said supporting plate, adjustable abutments for said arms disposed at opposite sides of said supporting plate, and means accessible from one side of said supporting plate for effecting adjustment of said abutments.

'7. A slack-thread controlling device for sewing machines comprising a supporting plate provided with an arcuate slot, alined stud-pins carried by said supporting plate to extend from opposite faces thereof, thimbles adjustably secured upon said stud-pins in spaced relation to the opposite faces of said supporting plate, coilsprings housed by and anchored to said thimbles, said coil-springs terminating in yielding thread-controlling arms extending between said thimbles and said supporting plate, stop-disks embracing said thimbles and providing spaced abutments for said arms, one of said stop-disks having an arcuate slot, and securing screws for said stop-disks passing through said supporting plate and stop-disk slots.

FREDERIC M. CARD. 

